Corrosion Resistance Properties of Porous Alumina–Mullite Ceramic Membrane Supports

Cost‐effective macroporous alumina–mullite membrane supports are fabricated by sintering coarse α‐alumina and colloidal silica, using cornstarch as the foaming agent at 1550 °C for 2 h in air atmosphere. To evaluate the corrosion resistance of such membrane supports, the corrosion behaviors of the supports before and after corroding in the H₂SO₄ and NaOH solutions (80 °C) are systematically investigated. Interestingly, with increasing Al₂O₃/SiO₂ ratio, the support presents numerous alumina grains and little glass phases, resulting in excellent corrosion resistance especially in acidic media. Benefiting from the alumina grains and little glass phases among the grain boundaries, lower mass loss, less variations in pore size and porosity, high residual strength, and an almost unchanged gas flux are obtained for a higher Al₂O₃/SiO₂ ratio support. The porous support, herein, is suitable for microfiltration membranes used in harsh environments.